/* ----------------------------------------------------------------------
 * Project:      CMSIS DSP Library
 * Title:        arm_dct4_init_f32.c
 * Description:  Initialization function of DCT-4 & IDCT4 F32
 *
 * $Date:        18. March 2019
 * $Revision:    V1.6.0
 *
 * Target Processor: Cortex-M cores
 * -------------------------------------------------------------------- */
/*
 * Copyright (C) 2010-2019 ARM Limited or its affiliates. All rights reserved.
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed under the Apache License, Version 2.0 (the License); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an AS IS BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "arm_math.h"
#include "arm_common_tables.h"

/**
  @ingroup groupTransforms
 */

/**
 @addtogroup DCT4_IDCT4
 @{
*/

/**
  @brief         Initialization function for the floating-point DCT4/IDCT4.
  @param[in,out] S          points to an instance of floating-point DCT4/IDCT4 structure
  @param[in]     S_RFFT     points to an instance of floating-point RFFT/RIFFT structure
  @param[in]     S_CFFT     points to an instance of floating-point CFFT/CIFFT structure
  @param[in]     N			length of the DCT4
  @param[in]     Nby2       half of the length of the DCT4
  @param[in]     normalize  normalizing factor.
  @return        execution status
                   - \ref ARM_MATH_SUCCESS        : Operation successful
                   - \ref ARM_MATH_ARGUMENT_ERROR : <code>N</code> is not a supported transform length

  @par           Normalizing factor
                   The normalizing factor is <code>sqrt(2/N)</code>, which depends on the size of transform <code>N</code>.
                   Floating-point normalizing factors are mentioned in the table below for different DCT sizes:

                   \image html dct4NormalizingF32Table.gif
 */

arm_status arm_dct4_init_f32(
	arm_dct4_instance_f32 *S,
	arm_rfft_instance_f32 *S_RFFT,
	arm_cfft_radix4_instance_f32 *S_CFFT,
	uint16_t N,
	uint16_t Nby2,
	float32_t normalize)
{
	/* Initialize the default arm status */
	arm_status status = ARM_MATH_SUCCESS;


	/* Initialize the DCT4 length */
	S->N = N;

	/* Initialize the half of DCT4 length */
	S->Nby2 = Nby2;

	/* Initialize the DCT4 Normalizing factor */
	S->normalize = normalize;

	/* Initialize Real FFT Instance */
	S->pRfft = S_RFFT;

	/* Initialize Complex FFT Instance */
	S->pCfft = S_CFFT;

	switch (N) {
#if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || defined(ARM_TABLE_DCT4_F32_8192)
	/* Initialize the table modifier values */
	case 8192U:
		S->pTwiddle = Weights_8192;
		S->pCosFactor = cos_factors_8192;
		break;
#endif

#if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || defined(ARM_TABLE_DCT4_F32_2048)
	case 2048U:
		S->pTwiddle = Weights_2048;
		S->pCosFactor = cos_factors_2048;
		break;
#endif

#if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || defined(ARM_TABLE_DCT4_F32_512)
	case 512U:
		S->pTwiddle = Weights_512;
		S->pCosFactor = cos_factors_512;
		break;
#endif

#if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || defined(ARM_TABLE_DCT4_F32_128)
	case 128U:
		S->pTwiddle = Weights_128;
		S->pCosFactor = cos_factors_128;
		break;
#endif
	default:
		status = ARM_MATH_ARGUMENT_ERROR;
	}

	/* Initialize the RFFT/RIFFT Function */
	arm_rfft_init_f32(S->pRfft, S->pCfft, S->N, 0U, 1U);

	/* return the status of DCT4 Init function */
	return (status);
}

/**
  @} end of DCT4_IDCT4 group
 */
